Electrical switch gear



May 13, 1924. 7 1,493,845

D. R. DAVIES ELECTRI CAL SWITCH GEAR Filed Jan. 23 1923 V 2 Sheets-Sheet Fig.4:

Q, A 24 2s T N G 461 f r /'59 z sai I '51 I I, INVENTOR David RDavieS.

4 ATTbRNEY 'WITN ESSES:

May 13, 1924' D. R. DAVIES ELECTRICAL SWITCH GEAR Filed Jan. 23 1923 2 Sheets-Sheet 3 E N l i b 3 g n #0 NP PQ ma Aw QM Em +m mm 5 @m 9. nm N v 3 2 mm am E A, a. n n .w |:|L L -i1\| l mm 3 Q a l .V 3 m l E W) |alhfllhhr h .1 hr nfihrd M0. N8 O8 98 AN v w an an .m. w i 2.

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INVENTOR David RDavieis.

ATTORNEY Patented May 13, 1924.

UNITED STATES PATENT OFFICE.

DAVID REGINALD DAVIES, OF MANCHESTER, ENGLAND, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY. A CORPORATION OF PENNSYLVANIA.

ELECTRICAL SWITCH GEAR.

Application filed January 23. 1923.

T 0 all whom it'mag concern:

Be it. known that I, DAVID R. DAVIES. a subject of the King of Great Britain, and a resident of Manchester, in the county of Lancaster, England, have invented a new and useful Improvement in Electrical Switch Gears, of which the following is a specification.

This invention relates to high tension electrical switch gear equipment of the kind comprising a plurality of switch gear units each having two or more enclosed switches and the object of the invention is to provide animproved system of mechanical interlocks between certain of said switches and the casings thereof for preventing possibility of access to any of said switches except under sai'econditions.

According to the invention, the interlocking is eiiected'by a system of locking bars slidably disposed in relation to the several switch gear units and capable of being moved to predetermined positions wherein access may be had to the mechanisms provided for releasing or removing the containers of the switches under consideration from their normal operative or closed positions, such movement of said locking bars being only permitted when certain of said switches are open.

The release or removal of the container of one or more switches prevents the locking bars being moved to positions which will permit the closure of any switch which can render alivethe contacts of the switch having its container released or removed. The locking bars are further adaptedto prevent the release or removal of any of the switch containers of a particular switch gear unit unless the switches thereof and the cor-- responding ad acent switches are in suchpositions as' completely to disconnect said unit from all conductors which are or may be alive. r

To enable the invention to be clearlv understood, it will now be described with reference to the accompanying drawings, wherein:

Figure 1 is an electrical diagram showing by way of example parts of the circuits of two switch gear units of the kind to which the interlocking arrangements according to the present invention may be applied.-

Figs. 2 and 3 are an elevation and a plan,

respectively, of interlocking mechanism ac- Serial No. 614,451.

cording tothe invention applied to. two

switch gear units of the type illustrated in lowering mechanism employed with the switch gear and also showing the interlocking bars and the bar shifting mechanism, and

Figs. 6 and 7 are respectively a sectional front elevation and a sectional plan of interlocking mechanism in accordance with the invention applied to a three-phase switch gear unit of the iron clad type.

Referring first to Fig. 1 of the drawings, 1 and 2 are duplicate bus-bars hereinafter referred to respectively as the main bus-bar and the auxiliary bus-bar to which are connected two or more identical or similar single phase switch gear units 3 and 4. Each switch gear unit comprises essentially a main circuit breaker '5, an isolating or disconnecting switch 6 for isolating one terminal of the circuit breaker 5 from the conductor 7 which latter may be, for example, the incoming cable/or feeder. The other terminal of the circuit breaker 5 is adapted to be connected with either the main bus-bar 1 or the auxiliary bus-bar 2 by means of alternatively operable selector switches 8 and 9 which witches are so interlocked with one another that they cannot both be closed at the same. time. It will be understood that each switch unit will comprise two sets of switches similar to the one described, only one being shown for the sake of simplicity. The circuit breakers 5 and the isolating and selector switche 6, 8 and 9 are usually of the oil-immersed type and will be hereinafterreferred to as such. The isolating or disconnecting switches 6 are provided with oil tanks 10 and the selector'switches 8 and 9 oi the switch gear units 3 and 4 are provided with oil tanks 11, 12, 13 and 14, res ectively, which tanks are removable as wil be well understood, for giving access to the switches. The switches 6, 8 and 9 and the operating mechanism therefor may be of any suitable type but they may be advantageously of the kind described and claimed in British patent applications Nos. 18964 and 18965 of 1921, and 25566 of 1922, all dated the 13th cated as having raising andlowering gear comprising winch mechanism consisting of ,ropes or cables 15 and winding drums 16,

17, 18 and 19 adapted to be rotated manually by a handle 20 which is provided w th a square 'or other I1011Cl1C11l{11 end 21 which is adapted to be engaged in a correspondingly shaped central opening 22 .111 the drums 16 to 19, inclusive, or in another part of the winch gear. The switch actuating inechansm, which is preferably of the kind described in the British patent application No. 18965 of 1921 above referred to, is not shown since it forms no part of the present invention but the main operation shaft thereof is indicated in Fig. 4 at 23 and this shaft 23 is adapted to be turned inone direction or the other for closing the isolating switch together with either the'main selector switches or the auxiliary selector switches by means of a cable or sprocket chain 24 from a shaft which may be disposed, for example, in a casing 26 located in the front of each switch gear unit as will be hereafter more fully described in connection more especially with Figs. 6 and 7 of the drawings; Keyed upon the shaft is'a pair of crank arms 28 and 29 (Fig. 4) pertainingrespect'ively to the main selector switches and the auxiliary selector switches. The ends of the arms 28 and 29 are, connected by depending links 30 and 31 respectively with rocking levers 32 and 33 securedupon auxiliary shafts 34 mounted in the bottom of the casing 26. The shafts 34 are provided with square or non-circular ends, as best shown in Fig. 7,

and are adapted to be turned by a removable'key or switch handle 27. The other ends of therocking levers 32 and 33 are connected respectively by means of upwardly extending links 35 and 36 with locking fingers 37 and 38'Which arepivotally mounted upon a shaft 39 at the back of the casing 26 and the purpose of which will .be

set forth later.

In Figs. 2 and 3 the mechanism 28 to 36, inclusive, is omitted for the sake of clearness and the locking fingers 38 are co'nventionally illustrated as being directly operated by the key or switch handle 27 when the latter is attached to a shaft 34.

' It will be understood that several switch gear units are arranged side by side and,

that any desired-number of such units may be provided in accordance with the requirements of the equipment which is tobe controlled thereby. The locking bars, according to the invention, are arranged parallel with one another for example in front of the several switch gear units in a-suitable casing. as will be hereinafter described in detail with respect more especially to Figs. 6 and 7.

()ne locking bar of the system is common to and extends completely across all of the switch gear units. This locking bar which will hereinafter for convenience be referred to asthe common locking bar is indicated at -10. The several switch gear units are individually provided with second locking bars hereinafter for convenience referred to as the "unit locking bars. These unit looking bars are arranged parallelwith the com mon locking bar and preferably severally in line with one another and are indicated at 41. The said bars 40 and 41 are preferably supported upon guide rollers as will be hereinafter described.

The common locking bar 40 is provided with a plurality of projections 42 corresponding in number to the number of winch operating spindles of thewhole switch gear equipment and the said projections which may be either secured to or integral with the bar 40 are so disposed on the latter that they cover the square or non-circular openings 22 in the winch drums 16,17, 18 and 19. lhe projections 42 are provided with circular holes or openings 43therein. The

openings 43 pertaining to each switch gear unit are so disposed in the projections 42 that the non-circular openings 22 in the winch drums of the main and of the auxiliary selector switch tanks, respectively, are never simultaneously exposed, that is to say, if the bar 40 is shifted so that the non-circular openings in the winch drums 17 and 19 pertaining-to the main selector switches 8 are exposed the winch handle 20 may be inserted through the openings 43 to engage such exposed winch drums so that anyor all ofthe tanks of the main selector switches maybe lowered. This being the case, the min-circular openings 22 in the winch drums 16 and 18 of the auxiliary selector switch tanks are not exposed by the correspondingopenings 43 so that the tanks of the auxiliary selector switches cannot be lowered.

The unit locking bais 41 are provided with projections 44 which are similar to the projections 42 on. the common locking bar 40 and are similarly spaced apart. The pro ections 44 on the unit. locking bars are also provided with circular holes or open ings 45 and the latter are so disposed in said projections that the non-circular openings 22 in the winding drums of the main and auxiliary selector switch tanks of each switch expose gear unit cannot be simultaneously The common locking bar and the unit locking bars 41 are provided with interlocking means as will be hereinafter described whereby the circular holes 43 and therein can only be both brought into line with the non-circular openings 22 pertaining to a tank of the main or the auxiliary selector switch of a unit when the main or the auxi liary switches respectively of all the switch gear units are open and when both them-aim and'the auxiliary selector switches" of the particular switch gear unit are open. This interlocking effect is obtained by the provision of further projections on the bars 40 and 41 which projections co-operate with the locking fingers 37 and 38 previously described ot' the several switch operating mechanisms.

The common locking bar 40 is provided with two downwardly extending projections 46 for each switch gear unit. The two projections 4-6 are so disposed on the common bar 40 that when the latter is in a central or neutral position they embrace the fingers 37 and 38 so thatrthe latter-may be permitted to rise when the switches are closed but that when the bar is shifted from its neutral position in either direction to an extent sufiicient to bring one of the holes 43 into line with a non-circular opening 22 in a rope drum. one or the other of the locking fingers 38 is so covered by the end of one of the projections 46 that said locking finger cannot be raised whereby the closure of the main or the auxiliary switch, as the case may be, is prevented. Thus referring to Fig. 2, when the common locking bar 40 is moved to the left so as to bring the holes 43 into line with the holes 22 in the drums 17 and 19 pertaining to the tanks of the main selector switches 8 it will be possible, if the unit locking bar is suitably shifted, to operate the. auxiliary selector switches but it will be impossible to operate the main selector switches by reason of the fact that the fingers 38 pertaining to said switches are covered by the right hand projections 46. Similarly. when the connnon locking bar 40 is moved to the right so that the holes 3 in the projections 42 expose the noncircular openings 22 in the rope drum lfland 18 pertaining to the tanks of the auxiliary selector switches 9 the right hand projections 46 will be clear of the locking fingers 38 so that it will be possible to operate the main selector switches while the left hand projections 46 willbe covered by the projections 37 pertaining to the main selector switches which therefore cannot be operated.

Furthermore, each unit locking bar 41 is provided with a single projection 48 extending downwardly in a similar manner to the projections 46. The width of the projection 48 is less than the distance between the locking fingers 37 and 38 so that when said projections 48 are intermediate the locking fingers 37 and 38 the latter may be both operated provided the common looking bar is in a suitable position. \Vhen, however, the unit locking bar is moved to the left, for example, in order to expose the non-circular hole 22 in the drum 17 or the drum 19 of a main selector switch the said projection 48 will cover the locking finger 37 pertaining to the main selector switch so that the latter cannot be operated, while the finger 38 pertaining to the auxiliary selector switch is not covered so that the latter can be'opemted. It will be understood that the projections 48 on the unit locking bar cooperate with the projections 46 on the com mon bar in such manner that it is necessary thatboth of the bars 40 and 41 should oc cupy definite positions before either of the locking fingers 37 and 38 can be released. It will be further seen that should the bars 40 and 41 be moved to such respective positions that either of the locking fingers 37 and 38 is uncovered and either the main or auxiliary selector switches operated, one or other of the. fingers 37 or 38 will be raised between two of the fingers 46 or 48 as is shown for example, in the right hand part of Fig. 2.

\Vith the finger 37 in this raised position, it willbe seen that it is impossible to move the projection 48 to the left so that it is impossible to bring the circular holes 45 in the projection 44 into alignment with the non-circular hole 22 in the rope drum 19 pertaining to the main switch 8 of that unit.

Or when the locking finger 38 is raised and the auxiliary selector switch closed. it will be impossible to move the hole 45 into alignment with the non-circular hole in the rope drum 18 pertaining to the auxiliary swit'ch tank 13. As will be seen, the projection 48 co-operates with the projections 46 so that it will be impossible to move the unit locking bar 41 unless both the main and the auxiliary selector switches of a particular switch 'gear unit are open. Furthermore, if any main selector switch of any one unitis closed and all the auxiliary selector switches of all the units are open the common locking bar 40 can only be moved to the right to bring the circular holes 43in the projections 42 of said bar opposite the non-circular holes 22 in the rope drum 16 and 18 for the auxiliary selector switch tanks in other switch gear units. Movement of the common locking bar 40 in the opposite direc- "tion for exposing the non-circular holes 22 in'the drums 17 and 19 ot the main selector switch tanks is impossible. Thus, in order to lower the tanks of either the main or the auxiliary selector switches of a particular switch gear unit. the common locking bar 40 and also the unit locking bar 41 on that particular unit must be moved to predetermined positions and this is only permitted by previously opening the main and auxiliarvselector switches of that unit.

For each of the tanks 11, 12, 13 and 14 there is provided in the common bar 40 a notch 49 andeach unit locking bar 41 is provided with a similar notch 50. .The notches 49 and 50 in the bars 40 and 41 respectively are so located in said'bars as to be in alignment with one-another when the said bars are in such a position that the tank of a switch may be lowered by the insertion of a winch handle 20 into a winch drum. For each of theswitch tanks 11, 12, 13 and 14 there is provided a pivoted locking finger 51 which when in its normal or lower position engages in said notches 49 and 50 but which may be raised aboutits pivot so that it no longer engages said notches.

Each of the tanks 11, 12, 13 and 14 is provided with a projection 52 which is so disposed that when the tank is raised to its completely closed position it will engage beneath the corresponding locking finger 51 and raise the same clear ofthe notches 49 and 50 in the locking bars 40 and 41. On the other hand, as soon as the tank is lowered the locking finger will fall into notches 49 and 50 and lock both the bars 40 and 41 against movement in either direction. When these conditions obtain, that is to say, when the common locking bar 40 and the unit locking bar 41 of a particular switch gear unit have been both moved so as to expose a winch drum on that particular unit, the several holes43 in the projections 42 of the common locking bar 40 are in position for permitting the access of a winch handle 20 to the winding drums of. the main or the auxiliary switch tank, as the case may be, of other switch gear units but in order to lower such tanks the units to which they belong must have their switches operated as above described in order that the unit bars may be moved in the manner necessary for permitting the winch handles to be opera- .tively inserted into engagement with the corresponding drums of such other units. Furthermore, when any tanks of a particular unit are lowered the projections 46 and" 48 on the locking bars, owing to the position which the latter must now occupy, are in the paths of the locking fingers 37. and 38 of the corresponding switch mechanisms so that the operation ,of the latter for closing the switches is prevented.

Referring now to Figs.- 6 and 7, interlocking. arrangements for a three-phase switch gear are shown in somewhat greater detail and the means provided for shifting the locking bars are also illustrated. In this latter, respect, reference is also made to Fig. 5. The three tanks of the auxiliary elector switches are indicated at 11 and the three tanks of the main selector switches are indicated at 12, the said switches being alternately arranged in pairs side by side as shown. The casing 26 containing the operating mechanism for the switches and the locking fingers 37 and 38 is arranged centrally in front of the switch tanks.

The locking bars 40 and 41 are enclosed in tubes 53 which are provided between the casing 26 and two casings 54 which contain units or preferably at either end of a plu rality of units. The locking bars 40 and 41 are guided between upper and lower pairs of grooved rollers'56'which may conveniently be located in lateral extensions of the casings 26 and 54 to which lateral extensions the tubes 53 may be attached.

The mechanism for shifting the common locking bar 40 may be of any suitable description and advantageously comprises a shaft- 57 extended through the casing 55 from front to back thereof, said shaft being provided with a crank 57 which engages the locking bar 40. The shaft 57 is provided outside the casing 56 with a handle 58 by means of which the said crank can be moved from one to the other of three positions, firstly,'oorresponding to a neutral position of interlocks, that is to say, when the bar 40 is in the center of its throw, secondly, a position on the left of its central position corresponding to that in which the main selector switch tanks are released, and thirdly, a position to the right of said central position corresponding to that in which the auxiliary selector switch tanks are released. The handle 58 may be. provided with a pointer 58 which cooperates with an indicator 59 having three divisions 60, 61 and 62 upon which are respectively designated the positions just above referred to. The cas- 68 in the lower part of the casing 54 through which the end of a winch handle may be inserted for the purpose of rocking the crank 64.

The crank 61- is adapted to occupy either a central position corresponding to neutral position of the interlock or a position to the left wherein the main selector switch tanks may be released or, thirdly, a position to the right wherein the auxiliary selector switch tauks may be released. The crank 64 is preferably provided with an extension 69 having three notches 70 therein corresponding to the three positions just above referred to, said notches 70 co-operating with a spring pressed plunger 71 projecting from a tubular casing 72. The said notching arrangement serves, as will be well understood, to register the crank 64: into either of its three operative positions to which it may be moved by the winch handle.

In the description previously given of the operating mechanism the non-circular holes 22 were described as being provided in the winch drums 16 themselves and this arrangement may be adopted where the tanks are not too heavy to permit their being directly raised by a winch handle. In cases, however, where such tanks are of such weight that reduction gear is necessary, the non-circular holes 22 may he provided'in pinions 73 suitably mounted at 74 within the casings 54. the said pinions gearing with larger pinions 75 attached to the winch drums, as clearly shown in Fig. 5. Access to the non-circular holes 22 may be had through holes 76 in the center parts of the casings 54.

Furthermore, all the main selector switch tanks of a switch gear unit may be raised or lowered by the winch mechanism 18 at the right hand side of the switch gear. the winch drum 18 comprising three parts as clearly shown in Figs. 5 and 7, from which the ropes or cables pass over sheaves 77 to the three tanks 12. Similarly, the winch mechanism at the left hand end of the switch unit may be arranged to raise and lower the three tanks 11 ot' the auxiliary selector switches. the ropes or cables passing over sheaves 78. It will be understood that in Fig. 7 the lifting arrangement for only one end of the tanks is shown and that there will be similar arrangements provided for the other end of the tanks, the winch drums 16 and 18 being mounted, for example. on

shafts 79 which extend to the back of the switch gear and carry further winch drums.

Thus. with the mechanism above described, the tanks can only be raised or lowered when the locking bars occupy predetermined positions and movement of the locking bars to such positions is only permitted when such selector switches are open as will render the removal of a tank safe.

The removal of a tank of one or more switches prevents the locking bars from being moved to positions which will permit the closure of any switch which can render alive the contacts of the switch having its tank released or removed. Furthermore, the locking bars prevent the removal of any of the switch tanks of a particular switch gear unit. unless the main or auxiliary selector switches thereof and the corresponding switches of other switch gear units of the equipment are also open, that is to say, the said unit must be completely disconnected from all conductors which are or may be alive.

Although the invention has been described by way of example as applied to winch gear for raising and lowering oil switch tanks,the locking bars may be employed for preventing the removal. by other forms of manually operated mechanism, of other forms of switch casing or container. The invention is also applicable to switch gears other than of the iron clad type, for example, switch gears of the cubicle type, and also to switch gears wherein the bus-bars are divided into sections which are adapted to be connected together by what may be termed bus-bar section switches. In this latter case, the interlocking system according to the invention may be provided between said bus-bar section switches, and bus-bar isolating switches on the one hand and the tanks or containers of certain or all of the said switches on the other hand, the object of the invention being an improved construction and arrangement of interlocks for preventing the switch containers ofcertain of them from being removed or opened for inspection of the switches or tor othcrpurposes except when said switches or their contacts are completely disconnected from all live bus-bars or conductors or sections thereof.

It will be understood that various modifications may be made in the details of construction and arrangement without departing from the scope of the invention.

I claim as my invention:

1. Switch mechanism comprising a plurality of switch gear units each having two or more switches, separate removable enclosures for the switches, means for operating the enclosures, a plurality of locking bars slidably disposed in relation to the several switch gear units and so interlocked with the switches thereof and the said operating means that movement of the said enclosures is permitted only when the switches are in a predetermined position.

2. The combination with a plurality of switch devices, separate removable enclosures therefor and operating means for the enclosures, of a plurality of interlocking bars associated with the operating means for rendering the said means inoperative except bars.

when the bars are in predetermined positions.

3. The combination with a plurality of vswitch devices, separate removable enclosures therefor and operating means for the enclosures, ot' a plurality of interlocking bars associated with the operating means for rendering the said means inoperative except when the bars are in predetermined positions, and means operatively connected to the switch devices for controlling movement of the said bars.

4. The combination with a plurality of switch devices, separate removable enclosures therefor and operating means for the enclosures, of a plurality of interlocking bars associated with the operating means for rendering the said means inoperative except when the bars are in predetermined positions, and means actuated by the said enclosures for controlling movement of the said The combination with a plurality of switch gear units each having a plurality of selectively operated switch device's, separate movable enclosures for the devices, and separate ope ating means for the enclosures, of a plurality of interlocking bars, one of which selectively controls the operation of the enclosure of a switch device in each unit and another ofwhich selectively controls the operation of the switches of but one unit,'the

' said bars serving to render the said means inoperative except when the bars are in predetermined positions.

G. The combination with a plurality of switch gear units each having a plurality of selectively operated switch devices, separate movable enclosures for the devices, and separate operating means for the enclosures, of a plurality of interlocking bars, one of which selectively controls the operation of the enclosure of a switch device in each unit and another of which selectively controls the operation of the switches of but one unit, the said bars serving to render the said means inoperative except when the bars are clectively controls the operation of the enclosure of a switch device in each unit and another of which selectively controls the operation of the switches of but one unit, the said bars serving to render the said means inoperative except when the bars are in predetermined positions, and means operatively connected to the said enclosures for controlling-the moven'ient of the said bars. H

8. Switch mechanism comprising a plurality of switch devices, separate removable enclosures for the said devices, means including a handle-operated winding drum for actuating the enclosures and a plurality of movable interlocking bars controlled by the switch devices for preventing operative connection of the handle for operating the drums except when the devices are in predetermined positions. v

9, Switch mechanism comprising a plurality of switch devices, separate removable enclosures for the said devices, means including a handle-operated winding drum for actuating the enclosures, a plurality of movable interlocking bars controlled by the switch devices for preventing operative connection of the handle for operating the drums except when the devices are in predetermined positions, and means connected to the enclosures for controlling movement of the said bars. a

In testimony whereof, I have hereunto subscribed my name this fifth day of J anuary, 1923. 1

DAVID REGINALD DAVIES. 

